1. Field of the Invention
The present invention relates to a sanitary napkin having laterally opposed leakage preventing portions on one side and extensions extending laterally outwardly beyond the leakage preventing portions. More particularly, the present invention relates to a sanitary napkin in which at least parts of the extensions can be folded back against a backsheet and fixed on an undergarment.
2. Description of the Related Art
It is required for sanitary napkins that a menstrual blood can be certainly absorbed by a liquid absorbent layer and never leaks out of the article while wearing. However, the conventional sanitary napkins are liable to deform when applied an external force due to a motion of a wearer. Therefore, if they are deformed in a state where the absorbency cannot be sufficiently exhibited, it is often the case that a menstrual blood will leak and clothing will be stained with the menstrual blood. Especially when the wearer walks, stands up, sits down, or takes exercise, the groin vigorously moves to easily cause a clearance between the worn article and the wearer's body. Therefore, the discharged liquid fL0ws from the clearance, causing so-called lateral leakage, so that the clothing is stained with the discharged liquid.
Therefore, there has been made a proposal to prevent the lateral leakage in Japanese Unexamined Patent Publication No. H8-280735 (280735/1996) and so on, in which leakage preventing walls are formed on two sides of the article to extend in a longitudinal direction, and wing portions are provided to extend outwardly from the leakage preventing walls. Upon wearing, the wing portions are folded back against the outer side of the crotch portion of the undergarment and fixed on the outer side of the crotch portion through an adhesive layer. On two sides of the article, pocket-like recesses are formed between the leakage preventing walls and the absorbent body. Therefore, even if a menstrual blood is not absorbed by the absorbent body but flows along the topsheet, it can be dammed up by the recesses, thereby preventing the lateral leakage.
In this conventional sanitary napkin, since the article is fixed on the undergarment, the mobility in conjunction with the undergarment can be highly maintained.
In the conventional sanitary napkin, however, it is not always that the wing portions are folded back at the same positions. As a result, the sanitary napkin may possibly be attached to the crotch portion of the undergarment in a rightward or leftward offset position. Particularly when the wearer is in a hurry for changing the sanitary napkin for a new one in fear of stains on clothing, it is often the case that the sanitary napkin is worn without being attached to the undergarment in proper position.
If the sanitary napkin is attached to the crotch portion of the undergarment in a sidewardly offset position, when the wing portions are folded back against the outer side of the crotch portion of the undergarment, there is a strong probability that the root ends of the leakage preventing walls provided on the body-facing side of the sanitary napkin will be positioned at the folds near the root ends of the wing portions. If the root ends of the leakage preventing walls are positioned at the folds, the leakage preventing walls near the edges of the crotch portion of the undergarment are liable to deform, thereby deforming the pocket-like recesses.
In addition, if a sideward pressure is applied to the crotch portion of the undergarment due to compression by the thighs, such pressure directly acts on the root ends of the leakage preventing walls, which are positioned near the edges of the crotch portion of the undergarment. Therefore, the leakage preventing walls are liable to deform, causing a clearance between the leakage preventing walls and the wearer's skin. Moreover, the pocket-like recesses are also liable to deform, deteriorating the effect of preventing the liquid leakage.